In recent years, as a packet transport technology, an MPLS-TP (Multi Protocol Label Switching-Transport Profile) technology is attracting attention. MPLS-TP is considered as a subset of MPLS (Multi Protocol Label Switching-Transport Profile). MPLS-TP has strengthened ability for operation and maintenance and reliability compared with MPLS.
In particular, concerning strengthening of reliability, an MPLS transport network (infrastructure which supports various communication services such as the internet and a leased line) which does not depend on IP (Internet Protocol) is being built. Also, in MPLS-TP, control plain (C-Plane) and data plain (D-Plane) are made independent, and even if failures occur in C-Plane, user traffic will not be influenced and highly reliable services are realized.
Technologies in relation to a MAC (Media Access Control) search system of an MPLS-TP apparatus are described, for example, in Patent documents 1-3.
Inventions described in Patent documents 1 and 2 learn combination of a MAC address and a receiving port and specify an output port.
Invention described in Patent document 3 is, in order to learn a MAC address corresponding to a destination IP address, one which is realized by using an ARP (Address Resolution Protocol) packet for solving it